Who can resist hazelnuts? They're the most consistently rewarding nuts. Lay your hands on this autumn's harvest of Kentish cobnuts (hazelnuts by another name) and you'll experience them when they are youthfully mild and juicy. As hazelnuts dry out or are dried for storage, their persona emerges, one that can make other nuts seem dull.

Bake them gently, and that haunting taste deepens and becomes utterly seductive. Added crushed to chocolate, roasted hazelnuts are the sine qua non of Nutella, and of the celebrated Gianduja confectionery for which Piedmont is so famous. Without hazelnuts, French praline is just a pile of caramel. Take hazelnuts down the savoury route, and they give you world-class dips, such as Catalan romesco.

Why are hazelnuts good for me?It seems that eating hazelnuts, and other tree nuts, can reduce your risk of cardiovascular disease. This is probably due to their impressive store of monounsaturated fat, vitamin E, and minerals, such as copper and magnesium, all of which reduce blood pressure and inflammation.

Hazelnuts are full of oil, but there's no evidence they are fattening. Quite the contrary: people on nut-rich diets often show weight loss. An explanation for this is that eating nuts stimulates the metabolism and makes you burn more calories. Another is that the high fat, protein, and fibre composition of nuts gives them the "fullness factor" in spades, so when we eat them, we are left feeling satisfied, not tempted to stuff our faces with less healthy foods.

Where to buy and what to payBuying hazelnuts with their skin on makes them a bit cheaper. Guide price: £13.50-£15.50 per kg (blanched), £9-£13 per kg (skin on).

2 Place in a baking dish or roasting tin – they should fit snugly. Toss with 2 tablespoons tbsp of the olive oil and plenty of salt and pepper, then cover the base of the dish with water. Cover with foil and roast for 45-60 minutes, or until a knife can slice easily through the largest beetroot.

3 While the beetroot bakes, make the dressing. Simply whisk the olive oil, verjuice and garlic together until thoroughly amalgamated. Stir in the nuts and herbs and season to taste with salt and pepper.

4 Once the beetroot is ready, let it cool enough to handle, then peel.

5 Cut the beetroot into generous bite-size chunks and toss with enough dressing to coat generously.

6 Serve warm or at room temperature.

Rosie Sykes is head chef of Fitzbillies and co-author of The Kitchen Revolution (Ebury Press, £25). To order a copy for £19.99 with free UK p&p, go to guardianbookshop.co.uk